Abstract
The purpose of the research is to study the operation, and calculate the construction elements of the undercarriage of a modular overpass used during the repair of underground urban utility networks. The overpass combines the bearing structure of the modular bridge and the automobile chassis, on which this structure is installed for its transportation. The overpass is designed for the passage of vehicles along it and used to eliminate traffic jams on city roads during the repair of city underground communal networks by installing it above the repair trench. The results of the indirect static method are presented. Based on the results of calculations, cross-sections of the axes of the undercarriage of the overpass are determined. The dependencies of change of internal forces in structures of the overpass on loading of rolling stock are obtained. The effect of loading from mobile vehicles on the structures of the overpass was investigated.